physical education. n. (Education) training and practice in sports, gymnastics, etc, as in schools and colleges. Abbreviation: PE. physâ²ical educaâ²tion. n. instruction in sports, exercise, and hygiene, esp. as part of a school or college program.
3. Stress/injury. Stress on the tissues or any type of injury in the mouth can cause canker sores. Since the sores are actually tiny ulcers, they can be caused by any kind of hard brushing or eating something that can cause bruises or lead to tissue inflammation in the mouth.
Injury or irritation. Any type of damage or injury to the mouth, for instance, when the inside of the cheek is accidentally bitten or scraped by broken or jagged teeth or poor-fitting dentures, can cause blisters (vesicles or bullae) or ulcers to form in the mouth.